The animal sacrifices of Mosiac Law do not cleanse the soul and conscience from sin. They must be repeated. Jesus the Messiah offered Himself as the Lamb of God. His sacrifice was only one time and did not need to be repeated. The Hebrew author clearly shows the superiority of Messiah in everything.
My translation and notes for Hebrews 10:5-18
Messiah’s Sacrifice Cleanses from Sin
5 For this reason when he came into the world, he said, “Sacrifice and offering is not what yous want, but yous have prepared a body for me.
[The Greek word for “prepared” is καταρτίζω katartízō. It means something “mended” as fishing nets in Matthew 4:21. Here the idea is Jesus’s fleshly body was prepared, then perfected by the things He suffered (Hebrews 5:7-9) to be THE perfect, sinless Lamb of God sacrificed for our sins (1 Corinthians 5:7)].
6 “Yous were not pleased with burnt offerings or sin-offerings.
[The emphasis of Hebrews 10:5-6 is Messiah, Jesus, God the Son, told His Father that “doing your will, Father, is more important than offering animal sacrifices].”
7 “Then I said, ‘Look! I am here (in the scroll of the book it is written about me) to do yours will, O God.’”
[Compare Psalm 40. The Old Testament prophets gave God’s message about the coming Messiah. It was revealed to them the many specific things so a man could be authenticated as THE Messiah. Israel would have no excuse. They would know Him. One sign was that He came to do His Father’s will (Luke 22:42 and Matthew 26:39). The Father’s will was for Messiah to be the perfect Passover Lamb for the sins of the world (1 Corinthians 5:7, 1 Corinthians 15:3-4, Isaiah 53:7-10, John 1:29, and 1 Peter 1:19-20].
8 When he said above, “Sacrifice, offering, burnt offerings, and sin-offerings yous didn’t want nor were pleased [with them],” which are offered by the law.
9 He then said, “See, I have come to do yours will, O God.” He abolishes the first, so that he may establish the second.
[The ‘first’ is the Mosaic/Sinaitic covenant which Messiah abolished. The ‘second’ is the New Covenant (Jeremiah 31) which Messiah established and sealed by His blood].
10 By that will we have been sanctified from the guilt of sin through the one-time sacrifice of the body of Jesus Christ.
[‘By that will’ refers to Messiah carrying out God’s will of Hebrews 10:7 and see Philippians 2:8].
11 Every priest stands day after day doing service and offering the same sacrifices over and over, which can never take away sins.
12 He [Jesus] himself, however, after he had offered one permanent sacrifice for sins, sat down on the right hand of God,
13 From then on waiting until his enemies are made his footstool.
14 For by one sacrifice, he has perfected forever those who are being sanctified.
[This is the one sacrifice Jesus gave on the cross. This sacrifice completely justifies any person who puts their faith and trust in Jesus alone. Our sanctification is an ongoing process as the Holy Spirit mold us to be in Jesus’s image of dedication and doing God’s will.
MacLaren (EXPOSITIONS OF HOLY SCRIPTURE) writes on this verse: The Old and the New Testament concur in this conception of ‘sanctity,’ or ‘holiness,’ which are the same thing, only one is a Latin word and the other a Teutonic one—namely, that it starts from being consecrated and given up to God, and that out of that consecration will come all manner of righteousness and virtues, beauties of character, and dispositions and deeds which all men own to be ‘lovely….and of good report.’
MacDonald (BELIEVER’S BIBLE COMMENTARY) writes: They have been perfected in a twofold sense. First, they have a perfect standing before God; they stand before the Father in all the acceptability of His beloved Son. Second, they have a perfect conscience as far as the guilt and penalty of sin are concerned; they know that the price has been paid in full and that God will not demand payment a second time].
15 The Holy Spirit is also a witness to us, because after what he had said previously,
16 “This [is] the covenant that I will make with them after those days,’ says the Lord, ‘I will put my laws into their heart, and I write them in their minds,
17 “’And I will no longer remember their sins and lawless actions.’” [Jeremiah 31:33-34]
18 Now where [there is] forgiveness of these, there [is] no more sacrifice for sin.
[We are forgiven when we are saved by grace alone through faith alone in Jesus Christ alone. It is finished. There are no more sacrifices for sins. Believers can now rest and rejoice in their Savior and in their salvation].